Anti-pollution laws create grave problems with respect to the continued use of internal combustion engines. The new laws establish regulatory authority with respect to all engines rather than to only automobile size engines. Exhaust emission standards for small power ranges, e.g. 15 to 50 horsepower, are foreseen as a natural consequence of these laws.
Inherently, a gas turbine engine is a low air polluting device. A major drawback, however, to the large usage of small gas turbines is their high cost relative to comparable size reciprocating engines. If such costs could be significantly reduced without a sacrifice in efficiency, it is considered that gas turbines in the 15 to 50 horsepower range could displace the reciprocating engine in many product areas.
It is accordingly a primary object of the present invention to provide a small gas turbine engine which, while at least as efficient as known designs, is considerably less expensive to manufacture.